Book nipping apparatus

ABSTRACT

Apparatus and a process used in book manufacture to nip or clamp a group of folded and sewn signatures which are assembled in preliminary manner, side by side, with the folded edges in a common plane to form the spine of the book, the nipping being accomplished by a two-stage jaw mechanism which initially clamps the signatures above the folds with firm pressure adequate to prevent slippage between adjacent signatures so as to prevent what is known as camel-backing in the completed book, while tightly compressing the folded ends of the signatures between jaws spaced a slightly greater distance apart to accommodate the slightly greater thickness of the assembled folded edges to effect a final folded set in said signatures.

United States Patent 1 Hall [ 1 May 8, 1973 [54] BOOK NIPPING APPARATUS [75] Inventor: Lewis William Hall, Lancaster, Pa.

[73] Assignee: The Maple Press Company, York,

[22] Filed: Aug. 2, 1971 [21] Appl. No.: 168,057

[52] US. Cl. ..l00/2l5, ll/l B, 100/218,

100/237, 100/264, 100/295 [51] Int. Cl. ..B30b 15/30 [58] Field of Search ..100/35, 295, 264,

100/215, 218, 237, 268, 296; l1/1CP, l B

[56] References Cited UNITED STATES PATENTS FOREIGN PATENTS OR APPLICATIONS 486,169 9/1952 Canada ..lOO/268 Primary Examiner-Billy J. Wilhite Attorney-C. Hercus Just [57] ABSTRACT Apparatus and a process used in book manufacture to nip or clamp a group of folded and sewn signatures which are assembled in preliminary manner, side by side, with the folded edges in a common plane to form the spine of the book, the nipping being accomplished by a two-stage jaw mechanism which initially clamps the signatures above the folds with firm pressure adequate to prevent slippage between adjacent signatures so as to prevent what is known as camel-backing in the completed book, while tightly compressing the folded ends of the signatures between jaws spaced a slightly greater distance apart to accommodate the slightly greater thickness of the assembled folded edges to effect a final folded set in said signatures.

14 Claims, 10 Drawing Figures PAIENTED 8W5 3.731.617

SHEET 1 OF 3 INVENTOR; [.iW/J W/LL/AM HALL ATTORNCY PATENTED 81975 3.731.617

SHEET 2 or 3 INVENTOR. LiW/S W/LLMM #4 1.1.

BY %W PATENTED W 81973 SHEET 3 [1F 3 INVENTOR. Lfw/s VV/LL/AM HALL BY BOOK NIPPING APPARATUS BACKGROUND OF THE INVENTION Bound books are composed of a series of folded signatures, usually of equal numbers of leaves. These signatures usually are stabilized by applying stitches through the folded edges thereof. A plurality of such signatures are arranged in side-by-side relationship incident to a coating of adhesive being applied to the folded edges of an assembly of such signatures in order to establish an initial relationship thereof prior to subjecting such assembly to further procedures.

It is a well-known fact that when a plurality of sheets of paper are folded while in overlying, assembled relationship, when they are released from the pressure which effects the folding, there is a tendency for the sheets or leaves to expand, especially the outermost leaves of the assembly. Accordingly, when a plurality of assembled signatures are disposed in side-by-side relationship, incident to being formed into a book, the practice in the manufacturing of books heretofore has been to place the folded edges of the assembled signatures under very great pressure in order to attempt to stabilize or substantially set the folded edges of the signatures in order to minimize any tendency of them to expand after release from the compressing means, following which the assembled signatures are passed along the book-manufacturing apparatus for further procedural steps to be undertaken.

One of the very commonly used pieces of apparatus to effect the compression of the assembled folded edges of signatures is in the nature of opposing clamp members which have auxiliary clamping means provided with spring means or similar mechanism by which the auxiliary clamping members project toward each other, beyond the clamping faces of the primary clamping members so as to engage the assembled signatures upwardly, or away from, the folded edges thereof in an attempt to secure the signatures against sliding movement relative to each other while the folded edges thereof are very firmly compressed by a number of tons of mechanical pressure in an effort to break the fibers of the paper and otherwise effect what might be termed final compressive folding of the signatures.

Due particularly, however, to the fact that very sub stantial compressive pressure is applied simultaneously to the folded edges of the assembled signatures to produce the desired folding effects, and particularly in the manufacture of books of substantial widths, such as of the order of an inch and a half or more in thickness, when such substantial pressures are applied against the folded edges of the assembled signatures, there is a tendency for at least a few of the signatures, usually in the central part of the assembly to overcome the limited clamping effect of the aforementioned auxiliary clamping jaws and bulge upwardly, away from the common plane in which the folded edges of the signatures initially are disposed and thereby produce a valley in the assembly, which is known in the bookmaking industry as a camel-back." The camel-back" phenomenon most commonly occurs during the nipping of assembled signatures which have been printed on an enameled paper stock.

The foregoing condition actually comprises a channel in the spine of the assembled folded edges of the 4 signatures, which extends inwardly from the plane of the spine. If this condition is permitted to exist, such as during the application of the binding to the book, and especially when the opposite edges of the assembled signatures are trimmed to produce a finished book, the product is of such nature that it is unacceptable for distribution to the trade and it must be discarded. No appropriate known, commercially usable methods for correcting the situation are available at present and books which include such conditions are unacceptable in the trade and therefore, comprise a waste.

SUMMARY OF THE INVENTION It is the principal object of the invention to provide in bookmaking apparatus or machinery, clamping means by which a plurality or assembly of folded book signa tures are disposed with the folded edges thereof against a common surface to form the spine of the book, said clamping means utilizing a pair of auxiliary clamping members which initially engage the assembly of signatures at a level above or otherwise spaced from the assembled folded edges of the signatures, initially in yieldable manner while relatively high-pressure type clamping means are moved into opposing relationship against the folded edges of the signatures but, prior to final, firm and positive clamping of such folded edges is achieved, the auxiliary clamping members are brought into positive non-yielding clamping engagement against the assembled signatures, in spaced relationship to the high pressure clamping means, so that when final clamping and creasing pressure is applied directly against the assembled folded edges of the signatures by said high pressure means, no relative slippage can occur between adjacent signatures and, therefore, any tendency to form camel-backs in the assembly of signatures is prevented.

Another object of the invention is to provide a pair of parallel high pressure jaws which are provided with seats within which longitudinally extending auxiliary jaws are mounted, and spring means are provided which act against the auxiliary jaws so as initially to dispose the gripping faces thereof outwardly from the gripping faces of the high pressure jaws, but during such aforementioned final compression of the folded edges of the assembled signatures, the yieldable pressure which initially is exerted by the springs against the auxiliary jaws is overcome and the auxiliary jaws then are firmly backed up by the high pressure jaws and, further, the final distance between the operative faces of the auxiliary jaws is slightly less than that between the operative faces of the high pressure jaws to effect firm, non-slipping pressure against the signatures in order that the final folding compression against the folded edges of the signatures by the high pressure jaws takes place to form a permanent folded set in the folded edges of the signatures while the same are held against any slippage between adjacent signatures.

A further object of the invention is to provide a reciprocably mounted head in the bookmaking machine or apparatus which supports the clamping jaws referred to above, said head beingreciprocable for a limited distance in opposite directions, parallel to the path of movement of the assembled signatures during engagement with the clamping means, said head preferably having a plurality of pairs of opposing clamping jaws so as to expedite the clamping operation and accommodate at least two assemblies of signatures at one time, the clamping of the signatures in the manner described above occurring while the head is moving in feeding direction for the signatures and upon the completion of a limited path of movement, the clamping means are released while the compressed and creased signatures are supported upon a horizontal surface and the head retreats to starting position for engagement of additional assemblies of signatures.

Still another object of the invention is to provide hydraulic m'eans upon the head for purposes of moving one jaw of each pair of pressure jaws and complementary auxiliary jaws toward and from the other and the other jaw of each pair preferably being adjustably positionable upon said head toward and from the path of movement of the signatures to accommodate the clamping means to assembled signatures of various thicknesses, within reasonable limits.

A still further, object of the invention is to provide both of said pressure jaws with auxiliary clamping jaws which initially are yieldably mounted thereon and are urged beyond the clamping faces of the pressure jaw by spring means of the type referred to above.

Still another object of the invention is to provide an elongated supporting plate upon which the assembled, folded edges of a group of signatures which are to form the spine of a book are slidably movable by advancing means, said elongated supporting plate extending through the reciprocable head referred to above, at a level below the clamping jaws, whereby the groups of signatures are suitably supported for movement along a common path provided by the upper surface of the elongated supporting plate while the signatures are being advanced to the clamping means and also while they are moved from such clamping operation to other operating mechanism utilized in manufacturing completed, bound books.

Details of the foregoing objects and of the invention, as well as other objects thereof, are set forth in the following specification and illustrated in the accompanying drawings comprising a part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat schematic top plan view of an exemplary bookmaking machine embodying the principles of the present invention.

FIG. 2 is a schematic side elevation of the bookmaking machine, shown in FIG. 1.

FIG. 3 is a perspective, fragmentary view ofa clamping head of the type employed in the bookmaking machine shown in FIGS. 1 and 2 but illustrated on a larger scale than shown in said figures for purposes of providing an understanding of the details of the clamping head and the clamping mechanism carried thereby.

FIG. 4 is a rear elevation of a pressure clamping jaw ofthe clamping units illustrated in FIG. 3.

FIGS. 5-8 respectively are sectional views of the clamping jaw shown in FIG. 4 as seen respectively on the lines 5-5, 66, 77, and 88 thereof.

FIG. 9 is a fragmentary enlarged end view of a pair of clamping jaws embodying the principles of the present invention and illustrated at the initiation of a clamping operation upon a group of signatures.

FIG. 10 is a view similar to FIG. 9 but showing the clamping jaws engaged with said signatures at the completion of the clamping operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a schematic layout of a typical book-manufacturing machine or apparatus is illustrated which employs clamping means that embody the principles of the present invention. Directing atten tion'to said figures, it will be seen that adjacent the lefthand end thereof, conveying and guide mechanism 10 is shown, which advances groups of folded signatures that ultimately are to comprise individual books. At this stage of the operation, the signatures which comprise equal numbers of leaves or pages are connected together by sewing which is performed at an earlier stage in the manufacturing procedure.

In guide mechanism 10, the individual assemblies or groups of a plurality of signatures are moved to transfer station 12 where they are advanced segmentally along a longitudinally extending, horizontal guide plate 14. Advancement of the groups of signatures along the guide plate is accomplished by means of an endless chain or belt 16, suitably guided. Said chain or belt certain details of which are better shown in FIG. 9, is provided with a plurality of laterally extending pushing pins or arms 18, which are of sufficient length to engage the trailing ends of assemblies of folded signatures which have individually been sewn to stabilize the leaves of each signature and also to hold the assembled signatures in initially assembled condition.

As the assemblies of signatures are moved along the guide plate 14, they pass over a conventional jogger 22 which serves to jostle the individual signatures, especially for purposes of evenly disposing the folded edges of all of the signatures slidably against the guide plate 14 prior to the same reaching the clamping unit 24 which is the feature of the entire machine with which the present invention primarily is concerned. Referring to FIG. 3, an enlarged, perspective view of the preferred construction of the clamping unit 24 is shown, details of which are as follows:

In FIG. 3, it will be seen that the head 26 is supported upon a base 28, see FIG. 2, by suitable means which permit the head 26 to be reciprocated in opposite directions, as indicated by the arrow 30 in FIGS. 1 and 3, by appropriate mechanical means, not shown, such as a rotating crank and link means, or otherwise, in order to permit the head 26 to traverse a distance preferably equal substantially to the length of the head in the direction of movement thereof. The construction of the head is such that a passage is provided therethrough to accommodate the guide plate 14 and the means directly below the same which supports it in rigid manner.

The head 26 also includes, preferably, a plurality of pairs of auxiliary or sub-heads 32 and 34, which respectively are guided toward and from each other in directions transverse to the path of movement of assemblies of signatures along the guide plate I4. Appropriate channels for guiding the pairs of auxiliary or sub-heads 32 and 34 with respect to each other are provided in the form of parallel guide members or blocks 36, 38 and 40, the blocks 36 and being similar, but the blocks 38 being of a compound nature so as to have guide means on opposite sides thereof respectively engaged with adjacent sides of the sub-heads 32 and 34. One auxiliary or sub-head of each pair preferably is adjustable longitudinally thereof in a direction transverse to the path of movement of the assembled signatures along guide plate 14.

In the specific illustration in FIG. 3, the sub-heads 32 are illustrated in association with exemplary adjustable means which comprise stationary anchor blocks 42 that are fixed to the head 12 and are provided with threaded apertures extending horizontally therethrough for the reception of threaded adjustment screws 44 having operative heads 46 on the outer end thereof for either manual or power-operated adjustment, as desired, of the screw to dispose the operative ends of the heads at desired transverse positions relative to the path of movement of assembled signatures along the guide plate 14.

The opposite auxiliary or sub-head 34 of each pair thereof preferably is actuated by power means, the specifically illustrated type of which comprises a hydraulic cylinder 48 and has an operative piston therein, not shown, which is movable through the operative end of each of the sub-heads 34. It will be understood that opposite ends of the hydraulic cylinder 48 are connected by suitable conduit means, not shown, leading to and from a source of fluid under pressure, in accordance with conventional construction, details of which are not believed to be essential in connection with the present invention.

Compound type clamping jaws are connected to the operative ends of each of the auxiliary or sub-heads 32 and 34. Such auxiliary clamping jaws each comprise a base or high pressure jaw 50 and an auxiliary clamping jaw 52. The pressure jaws 50 are provided with longitudinally extending seats 54, adjacent the forward and upper edge portions of the pressure jaws, said seats, in transverse view, being complementary in shape to the auxiliary clamping jaws 52. Each of said seats also has a substantially vertical rear wall or backup surface 56 against which the rear surface of each of the auxiliary clamping jaws 52 is adapted to abut during final positive clamping operation of a group of assembled signatures, as explained in detail hereinafter.

Referring to FIGS. 4-8, and especially to FIG. 4, it will be seen that the rear wall of each of the pressure jaws 50, which abuts against the operative face of the sub-heads 32 and 34, is shown with a plurality of phantom illustrations which represent various elements otherwise illustrated in detail in FIGS. 5-8. The spacing of the various elements illustrated in FIG. 4 has been selected to be advantageous operatively. Referring to FIG. 5 for example, it will be seen that the rear face of each auxiliary clamping jaw 52 is drilled to a predetermined depth to receive the threaded end of a headed movement-limiting bolt 58 which extends through bore 60 in the pressure jaw 50. Such bores and bolts are provided respectively adjacent opposite ends of the jaw 50.

At various spaced locations along the pressure jaw 50, spring-receiving bores 62 of limited depth are formed therein as illustrated in FIG. 6 and, at an opposing location in the auxiliary clamping jaws 52, corresponding bores 64 are formed for the reception of compression springs 66 of appropriate strength. Said bores and springs are of equal length and strength, respectively, so as to provide equal pressure between the clamping jaws 52 and pressure jaws 50 along the full length of-each. It will be seen that the springs 66 dispose the front or operative face of the clamping jaw 52, at least initially during the operation of the clamping means, at a substantial, predetermined distance forwardly from the gripping or pressure face 70 of each of the pressure jaws 50.

From FIGS. 5-10, it also will be seen that the gripping or pressure faces 70 of the pressure jaws 50 are along the lowermost portions of the jaws, immediately adjacent the longitudinal guide plate 14 so as to be in position to firmly engage opposing sides of the assembly of folded edges of the groups of signatures 20 with high pressure. In FIG. 9, the initial engagement of such assemblies of signatures 20 is illustrated in exemplary manner and in such arrangement, it will be seen that the auxiliary clamping jaws 52 are in the extended position thereof, similar to that illustrated in FIG. 6 and in which position they are maintained tentatively by the springs 66 which are capable of exerting a limited amount of pressure upon the auxiliary jaws and correspondingly, upon the signature assemblies 20.

Referring to FIG. 7, it will be seen that at longitudinally spaced locations along each pressure jaw 50, a limited number of threaded holes 72 are provided for purposes of receiving attaching bolts 74, which are shown in phantom in FIG. 7, by which the pressure jaws 50 are connected respectively against the operative faces of the sub-heads 32 and 34 of the clamping head 26. The headed ends of the attaching bolts 74 engage shoulders in bores 76 of larger diameter than the bolts 74, said bores extending appropriately into the subheads 32 and 34 from rearward portions thereof opposite the forward, operative faces. In FIG. 3, however, such bores are hidden from view by certain elements of the hydraulic cylinder units 48.

Referring to FIG. 8, it will be seen that a plurality of additional bores 78 are provided which extend inward from the rear face of the pressure jaws 50 for purposes of receiving positioning dowels 80, shown in phantom in FIG. 8, it being understood that the dowels are relatively short and extend in corresponding, axially aligned holes formed in the forward faces of the subheads 32 and 34.

Referring particularly to FIGS. 9 and 10, and also as seen from FIG. 1, after a plurality of assemblies of initially folded and stitched signatures have been jogged by jogger 22 and have moved along the guide plate 14 so as to respectively dispose the same adjacent the opposite pairs of pressure jaws 50 and their auxiliary clamping jaws 52, at which time the clamping unit or head 24 is in the full line position shown in FIGS. 1 and 3, suitable mechanism, not shown, is activated automatically to energize the hydraulic cylinders 48 to move the jaws 50 which are carried by the sub-heads 34 toward the jaws 50 carried by the sub-heads 32.

It will be understood that the sub-heads 32 have been adjusted previously by the screws 44 to enable the opposing pairs of pressure jaws 50 to receive therebetween assemblies of initially folded and stitched or sewn signatures 20 which are in an initial, somewhat reasonably compact relationship but nevertheless, are capable of readily sliding along guide plate 14 between the opposing surfaces of the auxiliary clamping jaws 52, as they are moved by the advancing movement of the chain or belt 16 and the pushing pins or arms 18 thereon. Such relationship between the assembled signatures 20 and operative faces 68 of the auxiliary clamping jaws 52 is illustrated in exemplary manner in FIG. 9, and in this position, it will be seen that the pressure faces 70 of the pressure jaws 50 and out of contact with or are at least in non-clamping engagement with the folded ends 82 of the signatures. However, it will be seen that all of the folded ends 82 are in immediately adjacent relationship and in slidable contact with the upper surface of longitudinal guide plate 14.

Following such initial positioning of the assemblies of the signatures between the respective pairs of pressure and clamping jaws 50 and 52, the power means comprising exemplary hydraulic cylinders 48 are energized to move the pressure jaws 50 on subheads 34 toward the opposing pressure jaws. As such movement continues, the springs 66 are compressed so as to cause the auxiliary clamping jaws 52 to be moved rearwardly toward and, finally, against the backup surface 56 of the pressure jaws 50. While this is occurring, the pressure faces 70 of the pressure jaws 50 are brought closer together and, by the time the auxiliary jaws 52 have been fully seated within the seats 54, and are positively in engagement with the backup surfaces 56, as shown in FIG. 10, the pressure faces 70 of the pressure jaws 50 will be disposed firmly in final high pressure and creasing position with respect to the as sembled, folded ends 82 of the assembly 20 of the signatures.

When the foregoing has occurred, the operative faces 68 of the auxiliary clamping jaws 52 are in firm, positive and spaced clamping relationship with respect to each other, against opposite faces of the assembly 20 of the signatures and the distance between the faces 68, under such circumstances, is slightly less than the distance between the pressure faces 70 of the high pressure jaws 50. The slightly greater space between high pressure jaw surfaces 70 is only adequate to accommodate the slightly greater width of the creased ends 82 of the compressed signatures than the thickness of the compressed leaves as engaged by jaw surfaces 68. Such firm and positive gripping of the assembly 20 of the signatures at a distance above or spaced from the pressure faces 70 will insure against any slippage occurring between the adjacent signatures of the assembly and thus, the folded ends 82 of all the signatures will remain flatly against the guide plate 14 so that no sliding movement of any of the folded ends 82 of the signatures relative to each other can or will occur.

In view of the foregoing, objectionable so-called camel-backing" will not occur during such final high pressure compression and creasing of the assembled folded edges 82 of the signatures, while the same are held in such firmly clamped condition to establish a substantially final set at the creased ends of the signatures while the head 26 moves from the receiving position thereof to the discharge position such as that shown in phantom in FIG. I, which illustration is intended solely to be exemplary rather than restrictive.

When the head 26 reaches the discharge position. hydraulic cylinders 48 are retracted or at least the pressure is relaxed to permit retraction thereof, depending upon the exact nature of the cylinders and operating means therefor, whereupon the pressure jaws 50 and their auxiliary clamping jaws 52, which are carried by the sub-heads 34, are moved away from the opposite pressure and clamping jaws carried by the sub-heads 32, whereupon reverse movement of the head 26 to the initial, loading position thereof, which is shown in full lines in FIGS. 1 and 2, may take place while the finally and firmly creased and compressed groups or assemblies of signatures 20 remain upon the guide plate 14 and may be moved longitudinally therealong by the propelling means comprising endless chain or belt 16 and the pushing pins or arms 18 thereon, such as seen in exemplary manner in FIG. 9.

It will be understood that the bookmaking machine illustrated in FIGS. 1 and 2 also may include appropriate guide plates respectively disposed in vertical manner adjacent opposite sides of the guide plate 14, which plates, not shown, may be adjusted to dispose the same in appropriate spaced relationship to form a guide channel for the assembled signatures while the same are moved by the means 16 and 18 successively to a secondary jogging unit 84, for example, to and through a glue-off station 86, where glue is applied to further secure the folded ends 82 of the signatures in assembled relationship, after which the same move through the glue-drying oven 88. Especially while moving through the oven 88, the assemblies of signatures are maintained in compact relationship by pairs of endless belts 90, the adjacent courses of which are disposed vertically and are supported by suitable stabilizing means which define a channel of precise width therebetween through which the assemblies of signatures move while the glue thereon is being dried.

From the foregoing, it will be seen that the present invention provides improved means for insuring positive and final creasing of the folded ends of a group of signatures which are toform a book and during the ap plication of adequate high pressure by the clamping jaws which move toward each other to effect such final creasing and folding, auxiliary clamping jaws positively and effectively secure the assemblies of signatures against relative sliding movement with respect to each other and thus, eliminate the difficulty of slippage occurring between adjacent signatures, especially those near the middle of an assembly of signatures of zip preciable width, which otherwise causes a groove or valley to form in the back or spine of the book which is finally manufactured from such assembly of signatures, such condition being known in the book manufacturing industry as a camel-back. The mechanism which accomplishes such improved type of clamping and creasing of the signatures is operable automatically and appropriate adjustment means are provided by which the apparatus may be adapted to accommodate groups of signatures of various widths or thicknesses.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as illustrated and described.

lclaim:

I. Book nipping apparatus comprising in combination a pair of parallel pressure jaws having clamping surfaces extending longitudinally thereof, means positioned below said jaws in use to support the spine portions of a group of assembled book signatures within a common plane extending transversely to the planes of said signatures, auxiliary jaw members carried by each pressure jaw at a level above the clamping surfaces thereof and parallel thereto, backing means on said pressure jaws engageable with and supporting said auxiliary jaw members to dispose the gripping surfaces thereof outwardly beyond the gripping surfaces of said pressure jaws a predetermined small distance to establish a final clamping relationship therebetween, yieldable pressure means positioned rearwardly of the gripping surface of at least one of said auxiliary jaw members and operable to extend the same beyond the final clamping position thereof and thereby permit initial yieldable engagement of a group of book signatures by said auxiliary jaw members above the folded edges thereof while said yieldable pressure means maintains said auxiliary jaw member in said extended position and means to move said one of said pressure jaws and the auxiliary jaw thereon toward the other pressure and auxiliary jaw until said yieldable pressure means has been overcome and thereby dispose said auxiliary jaw against said backing means on said pressure jaw and effect firm clamping of said group of signatures by said auxiliary jaw members above the spine portions of said signatures while positioned slightly beyond said clamping surfaces of said clamping jaws to prevent slippage between signatures while said folded spine portions are firmly compressed between said clamping jaws to effect a set fold in said signatures.

2. The book nipping apparatus according to claim 1 in which said pressure jaws respectively have elongated seats extending longitudinally thereof in the upper portions of the opposing faces thereof and said auxiliary jaws being disposed within said seats.

3. The book nipping apparatus according to claim 2 in which the inner wall of each seat is substantially vertical in use and provides a backup abutment wall engageable by the innermost surface of the auxiliary jaw seated therein to provide positive clamping by said aux iliary jaw when disposed against said inner wall of said seat.

4. The book nipping apparatus according to claim 3 further including substantially horizontal guide pins extending between said auxiliary jaws and pressure jaws adjacent said seats and operable to provide guided horizontal movement of said jaws within said seats during operation of said apparatus.

5. The book nipping apparatus according to claim 3 in which said auxiliary jaws and inner walls of said recesses are provided with longitudinally spaced pairs of axially aligned holes, and said apparatus further including compression springs disposed therein to urge said auxiliary jaws in spaced relationship to said inner walls.

6. The book nipping apparatus according to claim 1 further including a head, means to guide said head in reciprocating movement along the path of travel of assembled signatures in said apparatus, and means on said head supporting said pair of pressure jaws with the faces of said jaws parallel to the reciprocating movement of said head.

also including power means u on said head operable to move the other pressure aw oward and from said one pressure jaw.

8. The book nipping apparatus according to claim 6 in which said head includes a second pair of pressure jaws supported thereon in longitudinally spaced alignment with the first mentioned pair of pressure jaws thereon, and said apparatus including means operable to support said head for longitudinal movement for a distance at least equal to 'two groups of folded signatures longitudinally aligned upon said support means for signatures.

9. The book nipping apparatus according to claim 8 in which said support means comprises an elongated substantially horizontal plate extending through said head beneath said jaws and operable to support said groups of signatures while being compressed and also after being released by said jaws, whereby signatures after being compressed are supported for engagement by additional means when said head has been moved away from said compressed signatures to engagement with additional non-compressed signatures.

10. The book nipping apparatus according to claim 9 further including signature transfer means comprising a longitudinally extending member guided for movement parallel to said horizontal supporting plate and above said jaws of said head and provided with laterally projecting means extending into the path of movement of assembled signatures and operable to engage the trailing ends of said assembled signatures after the same have been creased and compressed and move the same along said supporting plate after release thereof by said jaws.

l l. The book nipping apparatus according to claim 6 in which the auxiliary jaws in both of said pressure jaws are spring-pressed toward each other by compression springs operable between said auxiliary jaws and said pressure jaws.

12. The book nipping apparatus according to claim 11 further including means connected to said auxiliary jaws and adapted to engage said pressure jaws to restrict outward movement of said auxiliary jaws to a predetermined extent.

113. The book nipping apparatus according to claim 6 in which said means to move said one pressure jaw toward the other comprises a hydraulic cylinder supported by said head and engaging said jaw.

14. The book nipping apparatus according to claim 13 further including means to adjust the other pressure jaw toward and from the opposite jaw and comprising a threaded anchor member fixed to said head, an adjusting screw operable therein and engageable with said jaw, and an auxiliary head supporting said jaw and guided upon said head for transverse movement thereon toward and from said other pressure jaw. 

1. Book nipping apparatus comprising in combination a pair of parallel pressure jaws having clamping surfaces extending longitudinally thereof, means positioned below said jaws in use to support the spine portions of a group of assembled book signatures within a common plane extending transversely to the planes of said signatures, auxiliary jaw members carried by each pressure jaw at a level above the clamping surfaces thereof and parallel thereto, backing means on said pressure jaws engageable with and supporting said auxiliary jaw members to dispose the gripping surfaces thereof outwardly beyond the gripping surfaces of said pressure jaws a predetermined small distance to establish a final clamping relationship therebetween, yieldable pressure means positioned rearwardly of the gripping surface of at least one of said auxiliary jaw members and operable to extend the same beyond the final clamping position thereof and thereby permit initial yieldable engagement of a group of book signatures by said auxiliary jaw members above the folded edges thereof while said yieldable pressure means maintains said auxiliary jaw member in said extended position and means to move said one of said pressure jaws and the auxiliary jaw thereon toward the other pressure and auxiliary jaw until said yieldable pressure means has been overcome and thereby dispose said auxiliary jaw against said backing means on said pressure jaw and effect firm clamping of said group of signatures by said auxiliary jaw members above the spine portions of said signatures while positioned slightly beyond said clamping surfaces of said clamping jaws to prevent slippage between signatures while said folded spine portions are firmly compressed between said clamping jaws to effect a set fold in said signatures.
 2. The book nipping apparatus according to claim 1 in which said pressure jaws respectively have elongated seats extending longitudinally thereof in the upper portions of the opposing faces thereof and said auxiliary jaws being disposed within said seats.
 3. The book nipping apparatus according to claim 2 in which the inner wall of each seat is substantially vertical in use and provides a backup abutment wall engageable by the innermost surface of the auxiliary jaw seated therein to provide positive clamping by said auxiliary jaw when disposed against said inner wall of said seat.
 4. The book nipping apparatus according to claim 3 further including substantially horizontal guide pins extending between said auxiliary jaws and pressure jaws adjacent said seats and operable to provide guided horizontal movement of said jaws within said seats during operation of said apparatus.
 5. The book nipping apparatus according to claim 3 in which said auxiliary jaws and inner walls of said recesses are provided with longitudinally spaced pairs of axially aligned holes, and said apparatus further including compression springs disposed therein to urge said auxiliary jaws in spaced relationship to said inner walls.
 6. The book nipping apparatus according to claim 1 further including a head, means to guide said head in reciprocating movement along the path of travel of assembled signatures in said apparatus, and means on said head supporting said pair of pressure jaws with the faces of said jaws parallel to the reciprocating movement of said head.
 7. The book nipping apparatus according to claim 6 in which said head further includes means operable to support one of said pressure jaws for adjustable movement transversely to the clamping face of said jaw, and also including power means upon said head operable to move the other pressure jaw toward and from said one pressure jaw.
 8. The book nipping apparatus according to claim 6 in which said head includes a second pair of pressure jaws supported thereon in longitudinally spaced alignment with the first mentioned pair of pressure jaws thereon, and said apparatus including means operable to support said head for longitudinal movement for a distaNce at least equal to two groups of folded signatures longitudinally aligned upon said support means for signatures.
 9. The book nipping apparatus according to claim 8 in which said support means comprises an elongated substantially horizontal plate extending through said head beneath said jaws and operable to support said groups of signatures while being compressed and also after being released by said jaws, whereby signatures after being compressed are supported for engagement by additional means when said head has been moved away from said compressed signatures to engagement with additional non-compressed signatures.
 10. The book nipping apparatus according to claim 9 further including signature transfer means comprising a longitudinally extending member guided for movement parallel to said horizontal supporting plate and above said jaws of said head and provided with laterally projecting means extending into the path of movement of assembled signatures and operable to engage the trailing ends of said assembled signatures after the same have been creased and compressed and move the same along said supporting plate after release thereof by said jaws.
 11. The book nipping apparatus according to claim 6 in which the auxiliary jaws in both of said pressure jaws are spring-pressed toward each other by compression springs operable between said auxiliary jaws and said pressure jaws.
 12. The book nipping apparatus according to claim 11 further including means connected to said auxiliary jaws and adapted to engage said pressure jaws to restrict outward movement of said auxiliary jaws to a predetermined extent.
 13. The book nipping apparatus according to claim 6 in which said means to move said one pressure jaw toward the other comprises a hydraulic cylinder supported by said head and engaging said jaw.
 14. The book nipping apparatus according to claim 13 further including means to adjust the other pressure jaw toward and from the opposite jaw and comprising a threaded anchor member fixed to said head, an adjusting screw operable therein and engageable with said jaw, and an auxiliary head supporting said jaw and guided upon said head for transverse movement thereon toward and from said other pressure jaw. 